Guest post by Mae Smith, University of Wyoming Extension Educator, Big horn County

As the days get longer and we start dreaming about spring, its time to do a little garden planning. The first step is to decide what you want to plant and how many. Read the seed packet or do your research to determine the plant’s special needs.

Many native seeds require stratification, which is a process that requires cold, moist temperatures for a specified length of time. If seeds were dropped outdoors, the seeds would naturally go through this process during the winter and spring. Since you’ve stored them in unnatural conditions, this process must be mimicked. Stratification varies depending on the plant species but can add a substantial amount of time to seed starting and may need to be started now.Most seeds sold in seed packets don’t require preparation such as stratification. However, some are best started indoors long before they’re planted to give enough time for crop production and maturation. Tomatoes and peppers are commonly started indoors 6-10 weeks before planting.

You’ll want to plant after there is little threat of a heavy frost. To find your the last frost date for your area, check the Wyoming Last Frost Map. The lower part of the Big Horn Basin has an average last frost date of May 11-20. Check the seed packet and count from that date on the calendar to know when to start seeds.

Keep in mind this is an average and there is no guarantee we won't get a frost in June. For example, this table shows us that on May 23rd in Worland there is still a 10% chance that the temperature will drop below 32 degrees F.

There are several things you’ll need for starting seeds indoors.

Container: In hardware stores you’ll find nice greenhouse dome trays designed for this purpose. Some even have the growing medium included. These are nice because they drain water from the bottom and hold the water and heat in the top. However you can also use your own materials like recycled plastic berry containers, or sour cream tubs with holes punched in the bottom.

Growing medium: It is really important to use a sterile seed starting mix. If you don’t, there is a higher chance of the soil harboring bacteria and diseases which will cause something called “damping off” where the seedlings die.

Water: Be sure to keep soil and seedlings damp. A light mist with a squirt bottle works well.

Light: Setting pots in a windowsill will cause long, weak seedlings that flop over. It is best to use cool fluorescent lights that are positioned low over the soil and are raised as the plants grow. Be sure not to cook the little plants!

When the plants have at least 2 true leaves, they can be transplanted into larger containers. Be sure to harden off the plants by moving them outdoors in the shade during the day for a while to acclimate them to being outdoors.